Method of fitting dies



Aug. a1, 1926. 1,598,178

W. A. VALENTINE METHOD OF FITTING DIES Original Filed March 13, 1920 INVEN TOR.

m WILLIAM A. VALENTINE Patented Aug. 31, 1926.

UNIEE STATEfi WILLIAM A. VALENTINE, OF, PHILADELPHIA, PENNSYLVANIA, ASSlG-NOR TO 111D- WARD G. BUDD MANUFACTURING COMPANY, OF PHILADELPHIA, PENNSYLVANIA,

A CORPORATION OF PENNSYLVANIA.

METHOD OF I ITTING DIES.

Original appIication filed. March 13, 1920, SerialNo. 365,333, Patent No. 1,466,259. Divided and. this application filed April 24, 1922. Serial No. 556,164.

My invention relates to an improved method of fitting dies and has to do, more particularly, with a method of fitting male and female dies such as are used in the manufacture of sheet metal stampings. This application is a division of my pending application for die fitting apparatus, Serial No. 365,383, filed March 13th, 1920.

Prior to my invention it has been the 10 practice especially in the ease of large heavy dies to the fitting of which my present invention more particularly relates to rough form the dies and then to place a set of such rough-formed dies in the press in which they are to be used and bring the male and female dies into working relation to each other. The irregularities of surface and contour on the opposedfaces of the die members are noted and the workmen grind, chip off, or otherwise remove and correct these irregularities while the dies are in the press, frequently bringing the dies into working rela tion ship with each other to note the degree with which they approach a perfect fit. This practice is objectionable because it is very wasteful andinefficient. In the firstplace, the presses in which the dies are used do not have a long enough stroke to permit a separation of the dies materially greater than is necessary to insert a blank or sheet of metal between them. The result is that there is very little room for the workman to work in fitting the dies and when he has inserted the necessary tools it is ditficult for the workman to watch the progress of the work and he is compelled to work in an awkward position. This makes the work of fitting the dies slow and tedious, adds materially to the cost of the fitting operation and makes it diflicult to secure a perfect fit. Furthermore, the press is withdrawn from productive work and stands idle during the fitting of the dies and, since these presses are very costly machines, the fact that the press stands idle for a considerable period also adds materially to the cost of fitting dies by this method heretofore practiced.

The object of my invention isto provide a method of making or fitting dies in which the above-noted objections are eliminated in that the workmen are given plenty of room to enter between and Work on the dies when fitting them and the dies can be fitted ready for use outside of the press in which they are to be used, so that the latter does not have to be withdrawn from productive workduring the fitting operation.

Further objects, and objects relating to details and economies of operation will definitely appear from the detailed description to follow. In one instance, I accomplish the objects of my invention by the method described in the following specification. My invention is clearly defined and pointed out in the appended claims. A method constituting a preferred embodiment of my invention is illustrated in the accompanying drawing, forming a part of this specification, in which:

Fig. 1 is a view in side elevation of a die fitting apparatus illustrating one way of carrying out my invention.

In the drawing the same reference numerals refer to the'same parts throughout the several views. y

In general my invention consists in disposing the dies to be fitted in opposed relation, the one above the other, and bringing their diefaces into surface contact with each other, but without pressure other than that caused by the weight of the upper .die resting on the lower die, in order to determine the surface irregularities which prevent a perfect fit of the two opposing die faces, then separating the dies a substantial distance apart, that is, to a distance sufficient to accommodate the workmenand to permit them to enter the space between the separated dies to effect the removal or correction of any surface irregularities found to exist therein, the dies being brought into contacting relation to each other as often as is desirable or necessary, during the fitting operation, for

completing the determination and removal of the surface irregularities. The surface irregularities of the dies may be determined by coating one or both of "the mating die surfaces withpaint or other coating material and noting the abrasion of such coat after the dies have been brought into contacting relation and then separated. I find it desirable to avoid the application of external pressure in bringing the mating die surfaces into con tacting relation. This may be accomplished in various ways, in accordance with my invention, According to one method, one of the dies may be permitted freedom of movement relative'to the other, that is, one of the dies may be suspended and lowered into contact with the mating die, so as to bear thereon by its own weight. H

According to one method of carrying out my invention, the rough-formed dies, 10 and 11, are fitted with respect toeach other by disposing them in opposed relation to each othorand suspending one of the dies so that it can be lOWGIGCtlIltOSUlIdCG con+ tact with the mating die. One or both of the mating surfaces of the, dies, 10 and 11, are, coated with a coat of paint and the suspended die,,1'1,.-is loweredinto gravity contact with the loweror fixed die, 10. o The surface irregularities, indicated somewhat conventionally, at '12, are determined by not ing the abrasion of the coateddie surfaces which may be observed after the dies have been separated. The dies, 10 and 11,. are then separated a substantial distance apart, that is to a distance sufficient to accommodate the workmen and to permit them to gain free access to the die surfaces for the purpose of removing'or correcting the surface irregularities determined by observation of the abrasions of the coated surfaces.

These irregularities may be removed or corrected by the use of anysuitable tools, such as the power driven chisel, 18,01 thegrinding wheel, 1%, by manual operation, or by any other suitable tools and, in accordance with my invention, the dies are separated so far apart tlia-tthe workmen can getzbetween them to operate these tools and observe the progress of the work, and the nature and extent of the irregularities tobecorrected or removed. 1.

I may suspend the die, 11, and lower it into gravity contact with the die, 10, to de term-ine the fit and the surface irregularities or imperfections, and then'raise the die, 11, a substantial distance to permit the workmen to get at the dies. In order to facilitate the determination of thesurface irregularities, it is desirable to. avoid any excessive pressure and, with that endjin view, I lower the die, 11, into gravity contact with the die, 10, and without the ap plication of any external pressure,that is, die, 11, exerts no pressureon die,10, other than that due to its own Weight and the weight of the member which carries it. In

the drawing, I have shown one-illustrative form of convenient apparatus for handling the dies, while fitting them in accordance with my invention, which comprises a base, 1.6, on which the die, 10, is supported, and a pair of spaced uprights or standards, 15, which are spaced a sutficient distance apart toallow plenty of room for the workmen to work on the dies. A carriage, 17, is mounted to slide on the ways, 18, provided on the uprights, 15, and the die, 11, is setor, 23. extend freely through suitable openlngs 324'. The said nuts are free to rotate, but are fixed against longitudinal movement on the rods, and are driven by shaft, 20, conneetedgbypulley, 21, and belt, 22, to me- The lower ends of the rods, 19,

into, recessesyorychambers, 26, in carriage, 17, and have fixed heads, 25, in such recessesf adapted to engage the upper walls thereof. his forms a suspending. support for the carriage with, a'slip connection between the suspension rods,'19, and the Can riage, 17, so that no external pressure is transmitted to the die, 11, and therods serve merely to raise the'carriage and the die and topermit the same to be lowered into. gravity contact of the die members, 11, 10. The motor, 23, maybe of such construction that it will drive the belt, 22,,in either directionat will,.or a reversing gearing may be employed for reversingthe di rection of the drive. then the motor is driven,.the shaft, 20, driving the nuts, 24, will cause the suspension rods, 19, to. ascend or. descend, raising or lowering the carriage, 17 and the die, 11... In my pending applicationfor die fitting apparatus, Serial No. 365,383,..fi1ed March 13th,.1920, I have shown andclaimed the apparatus, which I have just described generally, and in my pending fapplicationfor die fitting niachines,,Serial No., 365,38t, filed March 13th, 1920, I have disclosed and claimed another form of apparatus which is adapted for handling the -dies in carrying out the method of fitting dies disclosed and claimed herein;

It is to be noted that, in accordance with my method of fitting dies, the dies are brought into surface contact with each other without the application of any substantial external pressure; Consequently, the apparatus for handling the dies may be designed so as to provideplenty of room for which the dies are used. One of" the dies, 7

for instance, 11, may be a master die and the other die, 10, may be fitted with respect to this master, or both dies may be rough formed and then dressed in accordance with my invention until: their mating surfaces fit perfectly with respect to each other. The dies, 10 and 11, may be brought into gravity contact with each other as frequently as desired, during the fitting operation and then separated to renew the work on the die surfaces. The die surfaces may be brought into actual contact with each other, to determine the surface irregularities, or they may be brought into contact with a sheet of metal of the thickness of the stampings to be formed by the dies, so that the die surfaces are separated throughout by a distance equal to the thickness of the sheet of metal. I have used the terms contact and contacting relation in a sense including each of these conditions. In actual practice, I find it practicable to fit the dies by bringing the die surfaces into actual contact. I find it convenient to coatthe die surfaces in order to determine the surface irregularities but in some cases, the coating may be omitted and the surface irregularities determined by noting the abrasions on the die surfaces themselves. After the dies are fitted in the manner above set forth, they are then placed in the power presses and operated in the usual way. Thus it will be seen that the power presses are not required to be out of use while dies are being fitted together to replace those in use in the presses.

The process of my invention is of special value in fitting together the surfaces of large and heavy dies such as are employed in shaping large sheet steel stampings. I do not desire, however, to be limited or restricted in this respect.

I am aware that the method disclosed in detail herein may be varied considerably and may be carried out in a wide variety of forms of apparatus, without departing from the spirit of my invention and, therefore, I claim my invention broadly, as indicated by the appended claims.

Having thus described my invention, what I claim as new and useful and desire to secure by Letters Patent is:

l. The method of fitting dies which consists in disposing the dies with their mating surfaces in opposed relation to each other, bringing said surfaces into contact with each other to determine the surface irregularities of one or both die surfaces, separating said die surfaces a substantial distance apart to accommodate workmen in the intervening space, maintaining said dies in alignment throughout their relative movement, and removing said surface irregularities while the die surfaces are so separated.

2. The method of fitting dies which consists in suspending one of said dies with its die surface in opposed relation to the die surface of the mating die, lowering said suspended die into contact with the other die to determine surface irregularities of one or both of said die surfaces, raising said sus pended die to a substantial height to sepa rate the die surfaces sufficiently to accommodate workmen in the intervening space,

maintaining said dies in alignment during both lowering and raising operations, and removing the surface irregularities while said die surfaces are so separated.

3. The method of fitting dies which consists in suspending one of said dies with its die surface in opposed relation to the die surface of the mating die, coating one or both of said die surfaces, lowering the suspended die into contact with the other die under pressure to determine surface irregularities, limiting said pressure to a value less than that of the Working pressure of the dies, raising said suspended die so as to separate die surfaces a substantial distance apart to accommodate workmen in the intervening space, maintaining said dies in vertical alignment throughout said lowering and raising operations, and removing the surface irregularities while said die surfaces are so separated.

In testimony whereof, I aflix my signature.

WVILLIAM A. VALENTINE. 

